Starting circuit for electric valve apparatus



E. E. MOYER STARTING CIRCUIT FOR ELECTRIC VALVE APPARATUS Feb. 20, 1940.

ori inal Filed June 16, 1937 Pigl.

Inventor Elmo ElMoyer,

by His Attorney.

Patented Feb. 20, 1940.

STARTING CIRCUIT FOR ELECTRIC VALVE APPARATUS Elmo E. Moyer, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application June16, 1937, Serial No. 148,519

Renewed May 4, 1939 11 Claims.

My invention relates tostarting circuits for J electric valve apparatus and more particularly to are starting arrangements for electric discharge devices employing ionizable mediums.

Heretofo're there have been devised numerous arrangements for establishing arc discharges within electric valve apparatus or electric discharge devices employing ionizable mediums.

For example, in electric valve apparatus employing mercury vapor as the ionizable medium, there have been proposed numerous circuits for actuating a starting electrode to establish an arc betwen an auxiliary starting electrode and an to conventional type electric valve apparatus and l which is susceptible of wide application without necessitating material changes or'alterations in the main or power system.

It is an object of my invention to provide a new and improved starting circuitwfor electric valve apparatus employing ionizable mediums. 1

It is another object of my invention to provide a new and improved starting circuit for establishing an arc dischargewithin electric valve apparatus employing mercury vapor.

It is a further object of my invention to provide a new and improvedstarting circuit for mercury vapor discharge apparatus in which the circuit is responsive to the state of ionization of the mercury vapor to establish an arc discharge y as soon as the vapor becomes nonionized.

In accordance with the illustrated embodiments of my invention, 1 provide new and im- ,ionizable medium. For the purpose of illustration, I have shown my invention as applied to electric valve means employing cathodes of the self-reconstructing type, such as mercury pool cathodes, in which the ionizable medium is mercury vapor derived from the cathodes. In the arrangements illustrated, I employ a starting electrode biased away from the mercury pool cathodes and adapted to bemoved momentarily into engagement therewith. to establish an arc discharge. The auxiliary startingelectrode is actuated by an electromagnetic means which is energized by a resonant circuit comprising a saturable inductive device and a capacitance which are energized from a source of alternating current. When the inductive device is notsaturated, the device and the capacitance constitute a tuned resonant circuit and effect actuation of the auxiliary starting electrode. In order to con- 5 trol the saturation of the inductive device in accordance with the state of ionization of the ionizable medium, a circuit including a holding anode energizes the device to control the satura- 'tion thereofso that the device is saturated when 10 the medium is in an ionized state. When the medium is nonionized, the circuit resonates and reestablishes an arc discharge within the envelope of the electric valve means. i y

. For a better understanding of my invention, reference maybe had to the following description taken in connection with the accompanying drawing and its scope will: be pointed out in the appended claims. Fig. 1 of the accompanying drawing diagrammatically illustrates my invention as applied to an electric valve employing a mercury pool cathode and an auxiliary starting electrode which iselectro-magnetically operated by a resonant circuit of the series type, and Fig. 2 shows a similar arrangement in which a parallel resonant circuit is used. f

Referring now to Fig. 1 of the drawing, I have chosen to represent my invention as applied to an electric valve translating system for transmite ting energy between an alternating current circuit l and a direct current circuit 2 through a transformer 3 and an electric valve means 4. The electric valve means 6 comprises an envelope 5, anodes 6 and 1, associated control members or grids 8 and 9,holding anodes l0 and l, and a mercury pool cathode l2. Of course, the ionizable medium within the electric valve means 4 is mercury vapor. As a means for initiating an arc discharge within the envelope 5 and as a means for controlling the state of ionization of the ionizable medium, I employ an auxiliary starting electrode l3 which is biased away from the mercury pool cathode 12 by a spring member l8 and which is adapted to be moved momentarily into engagement with the mercury pool cathode I2 by a suitable electro-responsive means, such as a relaydevice l5 comprising a core mem ber l6 and an actuating or energizing coil H which acts on an armature member l4. A current limiting resistance (not shown), may be connected in series relation with the auxiliary starting electrode I3, if desired.

Iprovide a circuit 19, preferably a resonant circuit, including a saturable inductive device .20 and a capacitance 2| which are energized from a nection 25. includes a core member 26, a primary winding secondary winding 2d of transformer 23, and

suitable source of alternating current 22 through a transformer 23 having a secondary winding 24 provided with an electrically intermediate con- The saturable inductive device 2? which is connected in series relation with the capacitance it across the right-hand portion of also includesv a secondary winding 28 which is connected to coil ll of device it. By virtue of I the winding 28, the auxiliary starting electrode i3 is energized in accordance with an electrical condition of the circuit it), or in accordance with an electrical condition of the saturable inductive device EU. The secondary winding 28 of the inductive device 2!! is also connectedfto the cathode l2 and to the auxiliary starting electrode it through a capacitance 29 which serves to supply to the auxiliary starting electrode 03 a pulse of current sufficient to establish an arc discharge when the electrode i3 is momentarily moved into engagement with cathode l2.

As an agency for controlling the magnetization or the saturation of the saturabledevice 29 in accordance with the state of ionization of the mercury vapor of electric valve means 4, I provide anv energizing or holding circuit including holding anodes it and i i and current limiting inductances it which areconnected in circuit with primary, winding 27? of saturable device 29 and winding 2 L. This circuit transmits unidirec- 'clude a transformer 32, current limiting resist ances 33, and a source of negative unidirectional biasing potential such as a battery 34. The transformer 32 may be energized from any suitable source of alternating current, such as the circuit 8, through any conventional phase shifting ar= rangement such as the rotary phase shifter 35.

I The operation of the embodiment of my invention shown in Fig. 1 of the drawing will be considered when the system is operating to transmit energy from the alternating current circuit i to the direct current circuit 2 through transformer 3 andelectric valve means t. .When the mercury vapor is in an ionized state, the anodes 6 and i will conduct current alternately so that direct current is transmitted to the load circuit 2 in the manner well understoodbythose skilled in the art. Under these conditions, when the mercury vapor is in an ionized condition it will also be understood that the holding anodes it and H will conduct so that unidirectional current is transmitted from the cathode :12 through a'circuit' including winding 2? of inductive device 28, secondary winding 2 of transformer 231', inductances 3t and holding anodes It and I l. Under these conditions of operation, the undirectional current transmittedto winding 21 will effect saturation of the inductive device 29 so that the circuit i9 is made nonresonant. The voltage induced in secondary winding 28. of inductive device 20 will not be of sufiicient magnitude to effect actuation of auxiliarystarting electrode l3 saturable inductance 36 by the ionized, the circuit it will immediately respond to effect actuation of the starting electrode l3 to reestablish an arc discharge and to ionize the mercury vapor. More specifically, if the mer cury vapor becomes nonionized the circuits for,

holding anodes Ml and l i will not conduct current to winding 2? of saturable device 26, thereby increasing the inductance of this device to a value 'so that the inductivedevice 25 together with the capacitance 2i constitute a tuned resonant circuit. When thecircuit i9 is in a resonant condi- 'tion,the. voltage of the secondary winding 28 of device "29 will be materially increased so that the starting electrode i3 is actuated by the electromagnetic device l 5. As soon as the starting electrode i3 is brought into engagement with the mercury pool cathode 62, the coil ll of electromagnetic device i5 is eifectively shunted through i a circuit including the mercury pool cathode IE,

auxiliary electrode it, spring it andcapacitance 29; The electrode it will thereupon be moved away fromihe cathode l2 by the spring member l8, and due to the charge on the capacitance 29 an appreciable arc discharge will be drawn betweenthe electrode l3 and the cathode E2 to eifectionization .of the mercury vapor. As soon as the mercury vapor is ionized, direct current will be transmitted to winding 2? of device 2% to prevent. subsequent actuation of the electrode it. However, if the first arc fails to ionize the mer- "Icury vapor, the system will respond to actuate the electrode it until the mercury vapor becomes ionized.

Fig. 2 of, the accompanying drawing diagram ,matically illustrates another embodiment of my invention in which a resonant circuit of the parallel type is employed to effect energization of the control electrode of an electric valve means in accordance withthe state of ionization of the medium employed. The parallel resonant circuit includes a capacitance 35, and an, inductance 36, which maybe of the selfsaturating type, connected in parallel relation with the capacitance 35. vA suitable impedance, such as a resistance 31;.Inay beconnected-in series relation with the parallel connected capacitance 35 and inductance 36. Coil ll of relay i5 is connected to be energized in accordancev with the voltage appearing across the capacitance 35 and inductance 36.

The operation of the arrangement of my in- ,vention'shown in Fig. 2 is substantially the same as that ex'plainedinconnection wth the arrangementofLFig- 1. When the ionizable medium of the electric valve means t is nonionized, the parallel. resonant circuit including capacitance 35v and inductance 36 will be in a resonant condition and thevoltage appearing across these parallel connected elements will be sufficiently great to effect actuation of the electrode 53 by coil 27 of relay 15. As soon as-the electrode !3 is moved into'engagement with cathode i2, theccil ll will be, short circuited to effect deenergization of the coil l7, thereby'releasing the anode M and permitting the electrode late be moved away from the cathode l2 by spring 88, thereby drawing an arc and effecting ionization of the medium. When the, ionizable medium is in an ionized state, direct current will betransmitted through circuits including holding anodes liiand ii, current limitinginductances 30 and secondary windingt l of transformer 23. The direct current effects saturation yof the inductance 36 so that the resonant circuit is made dissonant, effecting thereby a material reduction in the voltage appearing across the parallel; connected capacitance 35 and inductance 36. When the circuit is dissonant, the voltage appearing across parallel connected capacitance 35 and the inductance 36 is not suflicient to effect actuation of the electrode l3 so that the elec trode is permitted to remain in the upper position so long as the medium is, in an ionized state.

As soon as the medium becomes nonionized, no

unidirectional current is transmitted to the in- .ductance 36, thereby restoring the circuit to the resonant condition :and increasing the voltage impressed on coilll to effect actuation of the electrode [3. The intermittent actuation of the electrode 13 will be continued until themedium 1 nections and as embodying various devices diagrammatically shown, it will be obvious to those skilled in the art that changes and modifications may be made without departing from my invention, and I, therefore, aim in the appended claims to cover all such changes and modifications as fall Within the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In combination, an electric discharge device including an envelope, an ionizable medium, an anode, acathode and an electrode for initiating an arc discharge within said envelope, a source of alternating current, a resonant circuit energized from said source, means for consource of alternating current, a resonant circuit energized from said source including an inductance and a capacitance, means for controlling said inductance in accordance with the state of ionization of said medium, and means energized in accordance with an electrical condition of said resonant circuit to energize said 'electrode when said medium is nonionized.

3. In combination, an electric discharge device including an envelope, an ionizable medium, an anode, a cathode and an electrode for initiating an arc dischargewithin said envelope, a source of alternating current, a resonant circuit energized from saidsource and comprising a parallel connected inductive impedance and a capacitive impedance, means for controlling one of said impedances in accordance with the state of ionization of said medium, and means energized in accordance with an electrical condition of said resonant circuit for controlling said electrode. j n 4. In combination, an electric valve means including an ionizable medium, an anode, a cathode, a holding anode and an auxiliary starting electrode, a source of alternating current, a circuit energized from said source including a serially connected saturable inductive device and a capacitance, said device and said capacitance being arranged to constitute a resonant circuit when said device is nonsaturated, a circuit in- Hcludingsaid' holding anode for saturating said device when said medium is ionized, and means responsive to an electrical condition of said device ior energizing said auxiliary electrode when ,said medium is nonionized. H 5, In combination, an electric valve means ineluding an ionizable medium,an anode, a cathj ode and an auxiliaryelectrode for initiating an arc discharge, a circuit including a source of ale .ternating current and a serially connected inductance and a capacitance energized from said said inductance so that said inductance and said capacitance constitute a tuned resonant circuit when said medium is nonionized and for making lish an arc discharge when said medium is nonionized.

6. In combination, an electric valve means,

having an anode, a cathode, a holding anode and an auxiliary electrode for starting an arc discharge, a circuit including a source of alternat ing current and a resonant circuit energized from said source including a serially connected inductance and a capacitance, said inductance being connected in circuit with said holding anode and said source and arrangedto be saturated to make said circuit nonresonant, when said medium is ionized, and means responsive to an electrical condition of said inductance for energizing said auxiliary electrode when said medium is nonionized. i

7. In combination, an electric valve including an anode, a mercury pool cathode, a holding anode and an auxiliary starting electrode biased away from said cathode and adapted to be movedv into engagement with said mercury pool cathode to initiate an arcydischarge, a circuit for energizing said holding anode, a source of alternating current, a resonant circuit connected to said source including a serially connected sat- .said circuit nonresonant when said medium is j ionized, and means energized in accordance with an electrical condition of, said resonant circuit for energizing said auxiliary electrode to estab-iz urable reactor and a capacitance, a circuit for i said holding anode, said reactor being controlled in accordance with the current of said holding circuit, and means energized in accordance with an electrical condition of said reactor to actuate 8. In combination, an electric valve means including an anode, a mercury pool cathode, a holding anode and an auxiliary starting electrode, electromagnetic means for actuatingsaid starting electrode to establish an arc discharge, a source of alternating current, a circuit energized from said source including a serially connected saturable reactor and a capacitance, an energizing circuit for said holding anode, said reactor being connected in circuit with said holding anode and arranged to constitute with said capacitance a resonant circuit when said electric valve means is nonconductive, and means responsive to an electrical condition of said reactor for energizing said electromagnetic means. i

9. In combination, an electric valve means having an anode, a mercury pool cathode, a holding anode and an auxiliary starting electrode biased away from said cathode and adapted to be moved into engagement with said mercury pool cathode to initiate an arc discharge, a source of alternating current, a circuit energized from said source including a capacitance ,50 i said electrode whensaid medium is nonionized. v

* and a saturable inductive device havinga primary winding connected in 's'eries relation with said capacitance and"'a' seo'ndary winding-for energizing said starting electrode,- afcircuit for said holding anode comprising said primary winding to control the inductance of said saturable' device in accordance with the conductivity ofsaid electric valve means, and means connec'tedto 'said secondary Winding for actuating said" elect'rode when said electric valve is nonconductive.

lOJI'n combination, an electric valve means empoyiin'g an ionizahle medium and including an 'anode,a cathode "and an electrode for initiating 1 an arc discharge, asource of alternating current, a circuit'energized from'said source including a t-seriall'y connected inductance and a capacitance, said circuit being resonant when saidinductance I is desaturated, a second circuit responsive to "'20 trolling the magnetization of saidinductance to theistateofionization of said medium for condesaturate said inductance when said medium is minimized and to saturate said inductance when said medium is ionized, and means energized-in'ac'cordance withan electrical condition of said inductance to energize said electrode when said medium is nonionized. I

'11. In combination, an electric valve means including an envelope, an ioniza'ole medium, an

anode, a cathode and an electrode for initiating an arc discharge Within said envelope, a source of alternating current, a resonant circuit energized from said source including a parallel connected capacitance and an inductance, means for supplying unidirectional current to said inductance to control themagnetization thereof in accordance with the state of ionization of said medium, and means energized inaccordance with the voltage appearing across said inductance and said capacitance for effecting energization of said electrode when said medium is nonionized. ELMO E. MOYER. 

